Mechanical pencil



Oct- 11 1949- J. A. MUsTARD MECHANICAL PENCIL Filed Feb. 23194'6 G, NWSN) AN. KN., QN

INVENTOR. lunes @Mmm- ITV W www5.. GN GQ 65N N Patented Oct. 11, 1949MECHANICAL PENCIL James A. Mustard, Janesville, Wis., assignor to TheParker Pen Company, Janesville, Wis., a

corporation of Wisconsin Application February 23, 1946, Serial No.649,472

(Cl. 1Z0-17) 13 Claims. 1

My invention relates to mechanical pencils and it has to do particularlywith so-called continuous feed pencils wherein a reservoir is loadedwith a plurality of leads which are fed therefrom in succession bymanually operable feed mechamsm.

Pencils of the foregoing type, as heretofore employed, have been ofcomplicated construction requiring a large number of parts involving arather high manufacturing cost. They have, therefore, necessarily beenexpensive to make, involving high cost to the user with considerablerepair expense. They also get out of order easily, requiring frequentrepairs. Further, much difficulty has been experienced with such pencilsbecause of lead breakage, particularly when thin leads are employed. Oneof the objects of my invention is to provide an improved pencil of theforegoing character and by which all of the foregoing objections havebeen overcome.

Another object is to provide a continuous feed pencil which is of verysimple construction wherein but few parts are employed, which parts areof sturdy and durable form and may be manufactured at low cost so thatpencils embodying my invention may be sold at a relatively low price.

A further object is to provide a pencil of the foregoing character whichalthough quite simple in construction, is adapted to give greatlyincreased writing efficiency with increased economy in the use of lead(thin or otherwise) through elimination of lead breakage.

An additional object is to provide a new and ncvel feed mechanismthrough which all of the foregoing features and advantages are attained.

A further object is to provide a fool-proof continuous feed mechanismwhich is subject to a minimum of wear and which receives a positive anduniform feed action for an indenitely long period of time.

A more specific object is tol provide a feed mechanism which is actuatedfrom opposite ends of the pencil, in thatl part of the actuation iseffected by pushing in the point of the pencil and the remainder byrestoring a push button at the rear end of the pencil, which push buttonis positioned by the aforesaid front end actuation whereupon it may beactuated to effect operation of the feed mechanism to propel the leadinto writing position. This arrangement provides an improved and facilefeed manipulation which greatly reduces the period of interruption inthe use of the pencil to effect lead feed.

Other objects and advantages of my invention 2 will be apparent from thedetailed description which follows, taken in conjunction with theaccompanying drawing, wherein:

Figure 1 is a longitudinal sectional view of an entire pencil accordingto a preferred embodiment of th-e invention and depicting the normalcondition of the pencil mechanism;

Fig. 2 is a longitudinal sectional view of the pencil, depicting thelead propulsion mechanism in the released condition;

Fig. 3 is a sectional view similar to Fig. 2 and depicting anintermediate step in the operation of the lead propulsion mechanism;

Fig. 4 is a perspective view of a split sleeve forming the tip end ofthe lead propulsion mech-y anism;

Fig. 5 is a transverse sectional view taken along line 5 5 of Fig. 1;and

Fig. 6 is a transverse sectional view taken along line 6-6 of Fig. l.

The pencil structure illustrated comprises an elongate hollow barrel Ito the front end of which is detachably connected a conically taperedtip member 2 having a bore 3 co-axial with lthat of the barrel.

Disposed within and reciprocable lengthwise of the barrel I is anassemblage which includes an elongate tubular member 4 closed at itsforward end by means of a plug 5 to which is connected a forwardlyextending clutch member 6.

Tubular member 4 has a compartment 8 forming a magazine in which may bestored a considerable number of writing leads which are adapted to befed out, one at a time, through the axial bore 9 of plug 5.

A cup-like pushbutton member I0 is slidably telescoped into the back endof tube 4 and is withdrawable therefrom.

An eraser I I is secured to member I0 by means of a threaded sheet metalsleeve I2. The subassembly comprising elements I0, II and I2 is aself-contained unit which upon withdrawal from tube 4, can be reversedso that eraser II projects from the back end of the pencil. An annularshoulder I3 formed in the bore of the barrel provides a stop againstwhich a shoulder 4a on the tube 4 abuts for limiting the forwardmovement of tube 4 which is shown in its forwardmost or writing positionin Fig. 1.

Clutch member 6 is an elongate tube of suitable spring material havingan axial bore large enough to freely receive the writing lead I4 and issplit lengthwise throughout a portion of its length, as shown in Fig. 5,to form three jaws 6a, 6b and 6c, which are disposed symmetrically 3about the bore portion 2al of the tip member 2 and the writing lead I4.Member 6 has an annular enlargement 6d, the forward portion of which isconically tapered as indicated at 6e.

Normally, in writing position, clutch member 6 is so positioned that theannular enlargement 6d is within the bore 2a of tip member 2, which boreis of a diameter such as to cause the aforementioned jaws normally to bemoved inwardly or contracted to grip the writing lead. Thus the leadnormally is held against retraction under ordinary writing pressure.

A portion of the bore of tip member 2 is conically tapered at 2b forengagement with a complementally shaped front end portion of the jaws6a, 6b and 6c in the normal or writing position of the clutch member toassist in holding the clutch jaws in uniform gripping engagement withthe writing lead.

Disposed within the bore of tip member 2 and at the front end of barrelI is a sleeve I5, which is shown in perspective in Fig. 4. This sleeveis split lengthwise throughout a portion of its length, as indicated atvIa, to afford a resilient lead gripping action, the bore thereof, at theforward end, being of such diameter that it always lightly grips thewriting lead and thus the sleeve server as a lead clutch. This grippingaction is sufficient to insure that the writing lead will move forwardlywith sleeve I5, as hereinafter described, when the lead is notrestrained by clutch member 6.

Sleeve I5 has a head I5b which normally engages a shoulder 2c formed intip member 2, and this provides a stop for limiting the forward movementof sleeve I5. Said sleeve is freely reciprocable lengthwise of thebarrel, but normally is yieldably held in its forward position, Fig. l,by means of a coil spring I6.

Situated at the rear of sleeve I5 and telescoped therewith is a secondsleeve II having an axial bore concentric with that of sleeve I5 andproportioned to slidably t the writing lead. Sleeve II has a rearexternal flange I'Ia which provides an abutment for the rear end ofspring I6. This sleeve is reciprocable lengthwise, being abutted by theforward end of clutch member 6.

In Fig. 1 the several parts are shown in the positions which they occupywhen the pencil is in readiness for writing-the writing lead I4 beingshown projecting from the forward end of sleeve I5.

Forward propulsion of the writing lead is accomplished by placing theprojecting tip end of the pencil (the projecting part of sleeve I5)against any convenient and suitable solid object and pressing the pencilthereagainst. This `immediately causes a rearward movement of sleeve I5into the barrel, as depicted in Fig. 2.

The rearward movement of sleeve I 5 is directly transmitted to sleeveI'I which, in turn, effects an equal rearward movement of clutch member6, plug 5, tube I and pushbutton II), together with eraser II and sleeveI2. This is clearly illustrated in Fig. 2. v

The rearward movement just described effects a rearward withdrawal ofenlargement 6d from the bore 2a, whereupon the jaws 6a, 6b and 6c moveor spring radially out of gripping engagement with the writing lead. Thelead is thereby freed from clutch 6 and is thus capable of being movedlengthwise relatively to the clutch jaws.

Following the above-described operation, the pencil may immediately bewithdrawn from the aforementioned solid object and, thereupon,

sleeve I5 is moved forwardly by spring I6, carrying with it the writinglead I4 while the other parts remain in the positions in which they areshown in Fig. 2. This is fully illustrated in Fig. 3, which, it will beseen, differs from Fig. 2 only in that sleeve I5 has been returned toits normal position with the spring IB expanded.

If now, push button I0 is depressed, clutch member 6 will be movedforwardly from the position in which it is shown in Figs. 2 and 3,whereupon the conically tapered forward portion 6e of enlargement 6dwill be engaged by the adjacent back end of tip member 2; and, as theclutch member continues to move forwardly, the jaws thereof will bedeflected inwardly into gripping engagement with the writing lead. Theclutch member 6 is so proportioned that the lead is gripped thereby justbefore enlargement 6d fully enters bore 2a, suitable allowance beingmade so that the grip of the jaws on the lead is sufcient to hold itfirmly, While at the same time the pressure required to forceenlargement 6d into bore 2a is not excessive. This pressure should atleast be enough to overcome the writing pressure, which otherwise wouldcause unwanted retraction of the clutch member and other parts.

The clutch 6 grips the lead shortly after the commencement of itsforward movement and at a point in its forward travel so chosen that theremainder of said forward travel is equal dimensionally to the distancewhich it has previously been determined the lead should project from thefront end of sleeve I5, as depicted in Fig. 1. As soon as the clutchjaws take hold of the lead, the latter moves forward with the clutchmember; but since sleeve I5 is already in its forwardmost position, thelead moves forward relatively thereto, notwithstanding the continuousgrip of said sleeve on the lead.

It will be noted that sleeve I'I always remains in abutting relationwith the forward end of the clutch 6 with its bore concentric with thoseof the clutch 6 and sleeve I5. In this way it connects the clutch boredirectly with the bore of sleeve I5 and gives a long and substantialsupport to the lead all the way from the clutch to the sleeve I5,thereby preventing lead breakage. It also ensures a substantiallycontinuous feed passage through the pencil by Way of the clutch andsleeves IT and I5 from the lead magazine so that the leads may be fedone after the other until all of the leads in the magazine are used up.The sleeve further ensures this action in that it serves as a positiveguide foran oncoming new lead from the clutch 6 in order that such newlead may properly propel a short unused lead section that is beingsupported forwardly in the bore of sleeve I5. With the foregoingarrangement, positive lead alinement is ensured and long and very thinleads may be employed without breakage within the operating mechanism.

It will be observed that the component parts of my new pencil arerelatively few in number', and all said parts are of such design thatthey inherently are easy to produce in volume and further such that thenecessary precision can readily be maintained. What is more, it will beevident that all assembling operations are simple and can be performedrapidly by unskilled workers. Thus, I have provided a very inexpensivepushbutton-operated pencil which is so simple and rugged that it islikely to remain in good Working order a very long time. In the use ofmy invention, thin leads may be employed without danger of breakage byoperation of the lead-feeding means. This is a distinct advantage,adding to the efficiency and long life of the pencil.

I have shown and described what I consider to be a preferred embodimentof my invention, but it will be obvious that there are a great varietyof possible modifications within the purview thereof and, accordingly, Ido not wish to be limited except as clearly indicated by the terms ofthe appended claims.

I claim:

1. The combination in a mechanical pencil, of a barrel, and leadpropelling means normally projecting from the front end of said barreland reciprocable lengthwise of the barrel to a limited extent, saidpropelling means including a clutch which normally grips the writinglead and holds it against rearward movement under normal writingpressure, said clutch being releasable in response to a rearwardlydirected releasing pressure applied to the front end of said propellingmeans that is greater than the normal writing pressure, and meansincluded in said propelling means for moving the lead forwardly to apredetermined limited extent when said releasing pressure isdiscontinued and while said clutch continues released, said clutch beingmanually operable, after being released, to re-engage the writing leadand move it forwardly an additional predetermined amount.

2. The combination in a mechanical pencil, of a barrel, and leadpropelling means normally projecting from the front end of said barreland reciprocable lengthwise of the barrel to a limited extent, saidpropelling means including a clutch which normally grips the writinglead and holds it against rearward movement under normal writingpressure, said clutch being releasable in response to a rearwardlydirected releasing pressure applied to the front end of said propellingmeans that is greater than the normal writing pressure, a push buttonoperatively associated with said propelling meansand means included insaid propelling means and operative upon discontinuance of saidreleasing pressure for moving the lead forwardly to a predeterminedextent independently of said pushbutton, said pushbutton being operativeto propel the lead forwardly an additional predetermined amount andconcurrently operative to actuate said clutch.

3. The combination in a mechanical pencil, of lead propelling mechanismnormally projecting from the front end of said barrel, a push buttonoperatively associated with said propelling mechanism and projectingfrom the rear end of said barrel, said mechanism including a clutchmember disposed within said barrel and reciprocable lengthwise thereof,said clutch member a forward position in which it grippingly engages thewriting lead and holds it against rearward movement under normal writingpressure and a rearward position in which it is disengaged fromthe-writing lead, said clutch member being movable to its rearwardposition by the application of a rearwardly directed pressure on thefront end of the pencil and movable to its forward position bydepressing said push button, said propelling mechanism including meansother than said clutch member for propelling the lead forwardly apredetermined amount upon discontinuance of said rearwardly directedpressure and while said clutch member remains in its rearward position,said clutch member vbeing further operative during its forward movementto propel the writing lead forwardly an additional predetermined amount.

4. The combination in a mechanical pencil, of lead propelling mechanismincluding a split sleeve disposed at the front end of the barrel andnormally projectingoutwardly therefrom, said sleeve being reciprocablelengthwise and having an axial bore adapted to accommodate a writinglead and to grip the same lightly, a spring continuously urging saidsleeve forwardly, a clutch member disposed within said barrel andreciprocable lengthwise thereof between a predetermined forward positionand a predetermined rearward position, and a push button projecting fromthe rear end of said barrel and connected with said clutch member, saidclutch memberbeing movable rearwardly by the application of an actuatingpressure on the front end of said sleeve and movable forwardly bydepressing said push button, said clutch member being operative inresponse to a forward movement thereof to grip the writing lead and moveit forwardly and to retain its grip on the writing lead while it remainsin its forward position, but ineffective to grip said lead when in saidrearward position.

5. The combination in a mechanical pencil, of a barrel having alengthwise extending bore opening at its front end, a sleeve mounted inthe front end of said bore and reciprocable lengthwise thereof to alimited extent, said sleeve having a lengthwise bore adapted toaccommodate a writing lead and to yieldably grip said writing lead, saidsleeve normally projecting a substantial distance out of the front endof said barrel and forceably movable rearwardly a substantial distancefrom its normal position, a clutch member disposed within said barrel atthe rear of said sleeve and reciprocable lengthwise of said barrel to alimited extent, said clutch member being movable rearwardly of thebarrel in response to a rearward movement of said sleeve, and manuallyoperable means for moving said clutch member forwardly, said clutchmember being operative in response to forward movement thereof to gripthe writing lead and advance thel same forwardly, said clutch memberbeing operative in response to rearward movement thereof to release thewriting lead, said sleeve being free to return to its normal positionindependently of said clutch member and operative when so doing to carrythe writing lead forwardly provided said clutch member is retained inits released condition during said forward movement of the sleeve.

6. The combination in a mechanical pencil, of a barrel having alengthwise extending bore opening at'its front end, a sleeve mounted inthe front end of said bore and reciprocable lengthwise thereof to alimited extent, a spring continuously urging said sleeve forwardly, saidsleeve having a lengthwise axial bore adapted to accommodate a writinglead and further adapted continuously to yieldably grip said writinglead, said sleeve normally projecting a substantial distance out of thefront end of said barrel, a clutch disposed within said barrel at therear of said sleeve and reciprocable lengthwise of said barrel to alimited extent, said clutch normally occupying a forward positionwherein it grippingly engages the writing lead and holds the sameagainst retraction due to ordinary writing pressure, means effective torelease the grip of said clutch on said writing lead in response to arearward movement of said clutch, said clutch being movable rearwardlyin response to a rearward movement of said sleeve and to an extentsucient to release its grip on adagiato/ the writing lead, meanseffective in response to a subsequent forwardmovement of said clutch tocause said clutch togrip the writing leadv` and? move it forwardly, saidsleeve being movable by said spring, independently of said clutch, toits` a barrel having a lengthwise extending boreA opening atiits frontend, a sleeve mounted in the front end of said bore and reciprocableIlengthwise thereof to a limited extent, a springcontinuously urging saidsleeve forwardly, said sleeve having a lengthwise axial bore adapted toaccommodate a writing lead and further adapted continuously to yieldablygrip said writing lead, said sleeve normally projecting a substantialdistance out of the front end of said baarrel, a clutch disposed withinsaid baarrel at the rear of said sleeve and comprising a plurality ofjaws which are conjointly operative and normally effective to grip saidwriting leadand hold the same against retraction under normal writingpressure, said clutch being reciprocable lengthwise of saidv barrel to alimited extent and normally occupying a position at the forward end ofits travel, means operative to contract said jaws intogrippingengagement with the lead and to hold said jaws so contracted except whensaid clutch occupies a rearward position, said means being effective tocontract said jaws at or near the outset of each forward movementA ofthe clutch from its rearward position, said clutch being movablevrearwardly, in response to a rearwardV movement of said sleeve, to aposition wherein the jaws are released, and manually operable means formoving said clutch forwardly, said sleeve being-movable forwardly bysaid spring to its rearward position independently of said clutch.

8. The combination in a mechanicalpencil, of

ar barrel having a lengthwise extending bore opening at its front end,,a first sleeve mounted" in the front end of said bore and reciprocable'lengthwise thereof to a limited extent, said'first sleeve having alengthwise axial boreadapted to accommodate a writing lead and furtheradapted continuously to yieldably grip saidA writing lead, said firstsleeve normally projectinga substantial distance out of the front end ofsaid barrel, a second sleeve disposed within said barrel at the rear ofsaid first sleeve and having anaxialbore coaxial with that of said firstsleeveA and of a diameter to slidably fit said writing lead', saidsecond sleeve being reciprocable lengthwise to a limited extentindependently of said first sleeve and movable rearwardly in response torearward: movement of said first sleeve, a spring interposedfbetweensaid first and second sleeves and continuously urging said first sleeveforwardly land said second sleeve rearwardly, a clutch member disposedwithin said barrel to the rear of'said` second sleeve and reciprocablelengthwise of'said` barrelf to a limited extent, said' clutch memberbeing engaged at its front end by said secondi sleeve and movablerearwardly thereby, said clutch member having an axial bore coaxialwithl the. bore of said sleeves for accommodating the writing lead andhaving jaw means for grippinglyvengaging the lead for holding the sameagainst 8Y fective so to do`r in response to and during each fullforward movement of the clutch member fromv its rearmost position, saidmeans being further operative to hold said jaw means actuated Whilesaid-clutch member remains in its forwardmost position, and push buttonmeans for propelling said clutch member forwardly, the arrangement beingsuch, firstly, that the writing lead is released from the grip of saidjaw means in response to a rearwardly directed releasing pressureapplied to said first sleeve, secondly, that said first sleeve isrestored to its normal forward position when said releasing pressure isreleased, carrying the lead forwardly with it and, thirdly, that thewriting lead is gripped and moved forwardly in response to a forwardmovement of the clutch member from its rearward position, thuspropelling the writing lead out of the front end of said first sleeve.

9. In a mechanical pencil having ra barrel, lead propelling mechanismycomprising a member reciprocably mounted in the writing :end of saidbarrel to support :and lightly frictionally grip the writing lend of. alead and normally .projecting from the writing end of said barrel,clutch means reoiprocable in said barrel, means to `hold said clutchnormally in firm clutching engagement with said lead within said barreland hold said clutch and lead l.against movement inwardly of the barrelaway from the writing end under normal writing pressure but releasingsaid clutch upon application of a pressure greater than normal lwritingpressure against :the writing end of said lead or said reciprocablymounted member to permit said clutch, reciprocably mounted member .andlead to be moved by such greater pressure, means to project saidreciprocably mounted member land advance said lead upon release ofpressure from the outer end of said member, and means connected withsaid clutch and projectingfrom the rear end of said barrel Aand manuallymovable inwardly in said barrel to return said clutch forwardly intocooperation with said holding means to cause said clutch to re-grip saidlead' and further advance said clutch a limited recipnocably mounted inthe writing end of saidv barrel to support and lightly fricztionallygrip the writing end of a lead and normally projecting from the writingend of said barrel, clutch means reciprocable in said barrel, meansclosely surrounding said lead between sfaid reciprocably mountedmemberand said clutch and engageable by both to transmit pressure from saidmember to said clutch, means to hold said clutch normally in firmclutching engagement with said lead within said barrel land hold saidclutch and lead against movement inwardly of rthe barrel away from thewriting end under normal writing pres-l sure but' releasing said clutchupon application of :a pressure greater than normal writing pr-essureagainst the writing end of said lead or said recipnoc-ably mountedmember to permit said clutch, reciprocably mounted member and lead to bemoved by such greater pressure, means to projecty said reciprocablymounted member and advance said lead upon release of pressure from theouter endof said member, and means connected with said clutch andprojecting from the rear` end of said barrel land manually movableinwardly in said barrel'to return said clutch forwardly into cooperationwith said holding means to cause said clutch :to re-grip said lead andfur- 9 ther advance said clutch a limited distance to propel said lead ameasured distance.

11. A mechanical pencil comprising la barrel, a i'lrst lead clutchreciprooable longitudinally in said barrel and including normally openjaws, clutch closing means positioned to engage said clutch, when thelatter is moved forwardly a predetermined distance, to close said jawsupon a lead therein and retain them closed during the remainder of theforward movement and eiective to retain said clutch in a forwardposition against normal writing pressure but not against :a rearwardlydirected releasing -pressure in excess of normal writing pressure, asecond lead clutch reciprocable longitudinally in said barrel with aportion adapted to project thereform, whereby said second clutch may bemoved rearwardly into said barrel by application of an externalreleasing pressure thereon, said second clutch being eiiective toconstantly exert a sufficient grip ion a lead therein to cause the leadto move therewith when said first clutch is in open condition, a drivingelemenit abutting said iirst clutch and slidable relatively to saidsecond clutch :and of such length as to have abutting driving relationwith said second clutch when both said clutches are in either theirforward or rearward positions, whereby rearward movement of said secondclutch when said rst clutch is forwardly of its rearward position iseffective to move said first clutch rearwardly to thereby release thelead, a spring between and resiliently urging said second clutch andsaid driving element apart, thereby resiliently maintaining the formerin projecting position except when moved rearwardly by the externalreleasing pressure, and a manually operable element for moving saidfirst clutch forwardly to advance the lead through said second clutch.

12. A mechanical pencil comprising a barrel open at both ends, a leadmagazine reciprocable in said barrel, a rst lead clutch reciprocab'le insaid barrel forwardly of said magazine and having a plurality ofnormally open resilient, leadgripping jaws, a second lead clutchreciprocable 45 in said barrel yforwardly of said rst lead clutch, and artip member having a forward, tapered body section and a rearward sleeveSection integral with and of less diameter than the adjacent rearwardend of said body section thereby defining a rearwardly facing shoulder,said sleeve section being threaded into the forward end of said bar-'rel with said shoulder abutting the forward end of said barrel toposition said tip, said tip member being formed with a bore having arearward enlarged portion for receiving and closing the jaws `of saidrst clutch against a lead therein upon movement lof said first clutch toa predetermined position within said tip and a forward reduced porltionreceiving said second clutch `for guiding the latter.

13. A mechanical pencil comprising a barrel open at its front and rearends, a tip member having a forward, tapered body section and a rearwardsleeve section integral with and of less diameter than the adjacent endof said body section thereby providing a rearwardly facing shoulder,said tip member being threaded int-o the forward end of said barrel withsaid shoulder abutting rthe forward end of said barrel, land having abore formed with a reduced forward portion in said body section forreceiving and guiding a forward lead clutch and an enlarged rearwardportion insaid sleeve section for receiving and actuating a rearwardlead clutch, a lead feeding mechanism including a lead magazinereciprocable in said barrel and projecting from the rear end thereof, aforward lead clutch reciprocable in the forward bore portion Iof saidtip and projecting forwardly therefrom, and a rearward lead-holdingclutch Ihaving normally open jaws and reciprocable in said rearward boreportion between a lead-gripping position in which said jaws are closedon a lead by the wall, said bore and a lead-releasing position in whichsaid jaws are disengaged from #the lead.

JAMES A. MUSTARD.

No references cited.

